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Solid organ transplants (SOT) are already very delicate procedures with many risks and complications involved. From infections, to rejections of the donor organ, and even death, just to name a few.
However, not many may know that there is a risk of one acquiring allergies from donor organs as well. Admittedly, the phenomenon is rare, but does occur. There are also many similar but different types of allergies that organ recipients can acquire. All would fall under the general term de novo allergies; allergies that develop in a person that had no previous history (Lee et al., 2025). Two types of allergies that will be focused on in this essay will be the donor-acquired allergies (DAA) and transplant-acquired food allergies (TAFA) (Lee et al., 2025).
Before discussing the risks and complications, one must know what exactly SOT are as well as what allergies are and their causes. Solid organ transplantations are highly invasive medical procedures that involve an organ from either a living or deceased donor being implanted into a receiver who has suffered from organ failure or catastrophic damage (Sciences, N. A. of, Engineering, & and Medicine, 2021).
Allergies occur when the body’s immune system overreacts to usually benign substances, though the exact causes as to why allergies develop in the first place are still to be determined (Sparks et al., 2024). It is said that genetic and environmental factors play a large role into how and why allergies develop, though to what extent is still not understood (Sparks et al., 2024). One theory to explain why allergies occur, and specifically why they are more prevalent in developed countries, is the hygiene hypothesis. In summary, the hygiene hypothesis proposes the idea that growing up in a highly sterile environment leads to an inexperienced, weakened immune system (Okada et al., 2010). One idea is that due to no threats being present, the body’s white blood cells- like eosinophils responsible for dealing with large parasites and allergic responses- become confused and overly sensitive. Thus leading to the body’s immune system to attack at the slightest provocation, which is exactly what happens with allergies and autoimmune disorders.
One interesting point to note is that DAA occurs mainly with liver transplants, although they have also been reported with heart transplants but less frequently (Marcuset al., 2018). The most common type of allergy to develop from liver transplants, or at least the most easily identifiable, are TAFA (Chang et al., 2025). Most likely due to the patients not realizing that they have developed said allergy and go on to consume previously safe foods, such as shellfish or peanuts, go into anaphylaxis, and then subsequently get diagnosed with DAA (Chang et al., 2025) (Evans, 2018).
The reason as to why DAA are more common with liver transplants is likely due in part to the important role the liver plays in the immune system. While the liver’s main functions are to produce bile and metabolize toxins, it is also a forerunner in the immune system- particularly regarding pathogens that enter the body through ingestion (Kubes et al., 2018).
In short, organ transplants are complicated surgical procedures that come with a myriad of risks. One risk that some may not be aware of are de novo allergies, allergies that develop without any previous history (Lee et al., 2025). The exact cause for why these allergies develop are largely unknown but theorized to be partially caused by the implanted organ as well as the medication prescribed to patients post operation (Marcus et al., 2018).
Works cited
Chang, J., Sousa, A., Flamm, S., Brown, L., Chan, E., & Sela, N. (2025). De novo shrimp allergy in an adult liver transplant recipient. Journal of Liver Transplantation, 18. https://doi.org/10.1016/j.liver.2025.100269
Evans, H. (2018). The Increasing Burden of Atopy and Allergy after Solid Organ Transplantation in Children. The Journal of Pediatrics, 196, 10-11.
Hansen, S. L., & Schicktanz, S. (2021). Exploring the Ethical Issues in Organ Transplantation: Ongoing Debates and Emerging Topics. In S. L. Hansen & S. Schicktanz (Eds.), Ethical Challenges of Organ Transplantation: Current Debates and International Perspectives (1st ed., pp. 11–20). transcript Verlag. http://www.jstor.org/stable/j.ctv371bwmp.4
Kubes, P., & Jenne, C. (2018). Immune Responses in the Liver. Annual review of immunology, 36, 247–277. https://doi.org/10.1146/annurev-immunol-051116-052415
Marcus, N., Amir, A., Grunebaum, E., Dipchand, A., Hebert ,D., Ng, V.,Walters, T., & Avitzur, Y. (2018). De Novo Allergy and Immune-Mediated Disorders Following Solid-Organ Transplantation—Prevalence, Natural History, and Risk Factors. The Journal of Pediatrics, 196, 154-160.
Needham, J. M., Nicholas, S. K., & Davis, C. M. (2015). Food allergies developing after solid organ transplant. Pediatric Transplantation, 19(8), 827–835. https://doi.org/10.1111/petr.12613
Okada, H., Kuhn, C., Feillet, H., & Bach, J. F. (2010). The ‘hygiene hypothesis’ for autoimmune and allergic diseases: an update. Clinical and experimental immunology, 160(1), 1–9. https://doi.org/10.1111/j.1365-2249.2010.04139.x
Parlar, Y. E., Ayar, S. N., Cagdas, D., & Balaban, Y. H. (2023). Liver immunity, autoimmunity, and inborn errors of immunity. World journal of hepatology, 15(1), 52–67. https://doi.org/10.4254/wjh.v15.i1.52
Sparks, R., & Nichol, A. (2024). Inflammation, immunity and allergy. Anaesthesia & Intensive Care Medicine, 25, 6, 399-405.
Sciences, N. A. of, Engineering, & and Medicine; Health and Medicine Division; Board on Health Care Services. (2021, June 30). Solid organ transplantation in the United States and the experiences of organ recipients and their caregivers. Exploring the State of the Science of Solid Organ Transplantation and Disability: Proceedings of a Workshop. https://www.ncbi.nlm.nih.gov/books/NBK573873/